A display device is used for various electronic products such as a mobile phone, a television receiver, and the like. A manufacturing process, a driving method, and the like of a display device is researched and developed in order to enlarge the screen and to obtain high definition.
Product development of a display device by increase in the number of pixels to enhance resolution is very active. Although resolution of the display device can be enhanced by increase in the number of pixels, the number of signal lines also increases with increase in the number of pixels. Therefore, as a countermeasure against increase of the signal lines, patent document 1 (Japanese Published Patent Application No. 2003-255903) discloses a structure that a decoder is provided in a pixel portion, and data in signal lines are distributed by the decoder circuit, and a signal line is shared between a plurality of pixels, whereby the number of signal lines is reduced.